Sighting apparatus for ordance.



PATENTED DEG. 18, 1906.

A. T. DAWSON & G. T. BUCKHAM. SIGHTING APPARATUS POR ORDNANCE.

APPLICATION FILED SEPT.29.1904.

TH: Nunn/s Pfrss cu.. WASHINGTON, 1::4 c.

UTTBD STATES ATENT OFFTOE.

ARTHUR TREVOR DAWTSON AND GEORGE THOMAS BUOKHAM, OF VEST- MINSTER, LONDON, ENGLAND, ASSIGNORS TO VICKERS SONS & MAXIM LIMTED, OF LONDON, ENGLAND.

Specification of Letters Patent.

Patented Dec. 18, 1906,

Application tiled September 29,1904. Serial No. 226.587.

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Be it known that We, ARTHUR Tnnvon DAW- SON, lieutenant of the Royal Navy, director and superintendent of Ordnance 'Vorlis, and GEORGE THoMAs BUCKHAM, engineer, subjects of the King oi Great Britain, residing at 32 Victoria street, Westminster, London, England, have invented certain new and useful Improvements Relating to Sighting Ap- Io paratus for Ordnance, ot which the following is a specification.

This invention relates to sighting apparatus for ordnance.

As is well known, the graduations on a I5 range-dial are ordinarily very close together at short ranges and more Widely spaced at long ranges, thus rendering the sight -scii ing operation dilli cult toperforni at short ranges, owing to the closeness ot the graduat ions and 2c the consequent ditiiculty in reading them correctly. This is a disadvantage which it is the chief object of our invention to remedy. so that the graduations on the range-dial will be equal or approximately equal throughout. For this purpose we interpose spiral-toothed gearing between the Worm-gearing for actuating the range-dial and the sight-elevating rack comprising either a pair of toothed Wheels gearing with cach other or a single 3o toothed Wheel gearing directly with the rack, so that the angular movement imparted 1o the range-dial by the sight-setting mechanism is regular or uniform or approximai ely regular or uniform, notwithstanding the variable nature of the movement that has i' o be imparted to the elevating-pinion in changing the range.

In order that our said invention may be clearly understood and readily carried into 4o etlect, We Will describe the same more iully with reference to the accompanying drawings, in Whichw Figure l is a side elevation ol siglnin g apparatus provided With our improved sightsetting and range-indicating mechanism in Which two spiral-toothed wheels are enif ployed. Fig. 2 is a side elevation showing the said sight-setting and range-indicati ing mechanism in which only one spiraLtooihed 5o Wheel is employed.

A is the usual bracket, Which is affixed to the gun-n'iounting and to Which the radial sight -bar A is hinged at a, said sight -bar l l l l having the usual laterally-displaceable pivoted holder or carrier a for the telescopic or other sight. B is the range-dial, and O the deHection-dial.

BX is the sight-setting hand-Wheel for elevating the sight-bar A through the intervention of the gearing hereinafter described, said hand-Wheel being situated at the side oi the sighting apparatus to permit of the latter being actuated by a separate sightsetter.

In Fig. 1 the range-dial B is mounted on the same axle b as the Worm-Wheel which is actuated by the Worm b2, carried by the horizontal axle b3, with which the hand- Wheel B is geared by means of bevel-gearing b4. b5 is the elevating-pinion for actuating the sight-rack b, said pinion being mounted onan axle 57, situated in close proximity to the said Worm-wheel axle b. The axle b, carrying the Worin-Wheel b and the range-dial B, is geared with the axle 67, carrying the elevating-pinion b5, by means of two toothed Wheels bs b", the pitch-lines of Which are spiral. These tWo toothed Wheels are so arranged that when the range-dial is at its zero position-fi. e., the position in Which it is shown in Fig. l-the largest diameter of the Wheel b9 will be gearing with the smallest diameter' of the wheel bs, and the form of the spiral is such that although the elevation of the sight-rack is variable-i. e., diminishes at ditlercnt parts of its movement in accordance With the increments of the range at which the gun is to be iired-the range-dial performs a regular or uniform movement, so that the degrees or graduations thereon for indicating the elevation are equal or approximatcly equal throughout. lhen We use this arrangement, We sometimes arrange, for the salie of facilitating the sight-setting, that one revolution of the sight-setting hand- Wheel BX gives, say, two hundred yards range indication on the range-dial, so that a quarter ol a revolution of said hand-Wheel would indicate iifty yards and a half-revolution would indicate one hundred yards on the range-dial.

Tn the arrangement illustrated by Fig. 2 We dispense With the separate axles for the Worm-Wheel b and the elevating-pinion b5 and employ only one axle-viz., the Worm- Wheel axle b, which also carries the range- IOO dial-and one spiral-toothed wheelb. This toothed wheel takes the place of the elevating-pinion b5 and gears with the sight-rack b, which has the pitch of its teeth so arranged that the teeth will always remain in gear with the teeth of the spiral pinion b9. In the example illustrated in this case the divisions or graduations of the range-dial will not be absolutely equal throughout, but will only be approximately equal. They will, however, be such that their distance apart will be considerably greater at short ranges than is practicable with the usual sight-setting mechanism.

The range-dial revolves in a stationary ring B', having a pointer B2. Y

What We claim, and desire to secure by Letters Patent of the United States, is-

1. In gun-sighting apparatus the combination of a sight-elevating rack, a range-dial, gearing for actuating said dial, and flat spiraltoothed gear interposed between the sightelevating rack and the actuating-gearing and in a position parallel with the dial, for the purpose specified.

2. In gun-sighting apparatus the combination of a sight-setting rack, a range-dial, gearing for actuating said dial, and a plurality of flat spiraltoothed wheels engaging with each other, said toothed wheels being interposed between the sight-setting rack and the actuating-gearing and in a position paallel with the dial, for the purpose speci- 'tie 3. In a gun-sighting apparatus the combination of a sight-setting rack, a range-dial, worm-gearing for actuating said dial and a plurality of spiral-toothed wheels engaging with each other and interposed between the sight-setting rack and the actuating-gearing for the purpose specified.

4. In gun-sighting apparatus the combination of a sight-elevating rack, a range-dial7 an axle carrying said dial, a worm-wheel on said axle, a worm engaging with said wormwheel, means Jfor actuating said worm, a spiral-toothed wheel mounted on said axle7 a second spiral-toothed wheel carried by an axle parallel to said dial-axle and gearing with the irst-mentioned spiral-toothed wheel, and a pinion carried by the parallel axle for engaging with the sight-elevating rack, substantially as and for the purpose specied.

In testimony whereof we have hereunto set our hands, in presence of two subscribing witnesses, this 14th day of September, 1904.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUOKHAM.

Witnesses:

HENRY KING, HERBERT H. FIELDING. 

